OBJECTIVES: I. Determine the response rate, in terms of achieving complete hematologic remission, partial hematologic remission, hematologic improvement, partial response, or back to chronic phase status, in patients with blastic phase chronic myelogenous leukemia treated with troxacitabine. II. Determine the proportion of patients whose disease returns to chronic phase and remains at that level for at least 3 months when treated with this drug. III. Determine the toxicity profile of this drug in these patients. IV. Determine the duration of survival of patients treated with this drug.